International troops opened fire on a bus carrying Afghan civilians Monday, killing four people, officials said. NATO and Afghan authorities declined to identify the international forces involved by nationality, AP reported. Elsewhere in the city of Kandahar, three suicide bombers attacked an Afghan intelligence services compound, but security forces who opened fire repelled them, said the spokesman for the government of the surrounding province, also called Kandahar. Four intelligence agents and six civilians, including a teacher at a nearby school were wounded in the attack, said the spokesman, Zelmai Ayubi. Five members of a single family were killed and two wounded in a roadside bombing in the Bala Buluk district of the northwestern province of Farah on Monday afternoon, according to provincial spokesman Ahmad Farid Ayubi. There was no immediate claim of responsibility.